Cartridge for the preparation of beverages

ABSTRACT

A cartridge containing one or more beverage ingredients and being formed from substantially air- and water-impermeable materials, said cartridge comprising an inlet for the introduction of an aqueous medium into the cartridge, and an outlet for a beverage produced from said one or more beverage ingredients, wherein said cartridge comprises an outer member, an inner member inserted in the outer member and means for producing a jet of the beverage, wherein said means for producing the jet of the beverage comprises an aperture in a beverage flow path linking the inlet to the outlet, characterised in that the aperture is delimited by an interface between the inner member and the outer member.

RELATED APPLICATION

[0001] This application claims priority from U.S. provisional patentapplication No. 60/462,538, filed Apr. 11, 2003, which is herebyincorporated by reference.

BACKGROUND

[0002] The present invention relates to a cartridge for the preparationof beverages and, in particular, to sealed cartridges which are formedfrom substantially air- and water-impermeable materials and whichcontain one or more ingredients for the preparation of beverages.

[0003] It has previously been proposed to seal beverage preparationingredients in individual air-impermeable packages. For example,cartridges or capsules containing compacted ground coffee are known foruse in certain coffee preparation machines which are generally termed“espresso” machines. In the production of coffee using these preparationmachines the coffee cartridge is placed in a brewing chamber and hotwater is passed though the cartridge at relatively high pressures,thereby extracting the aromatic coffee constituents from the groundcoffee to produce the coffee beverage. Typically, such machines operateat a pressure of greater than 6×10⁵ Pa. The preparation machines of thetype described have to date been relatively expensive since componentsof the machine, such as the water pumps and seals, must be able towithstand the high pressures.

[0004] In WO01/58786 there is described a cartridge for the preparationof beverages which operates at a pressure generally in the range 0.7 to2.0×10⁵ Pa. However, the cartridge is designed for use in a beveragepreparation machine for the commercial or industrial market and isrelatively expensive. Hence, there remains a requirement for a cartridgefor the preparation of beverages wherein the cartridges and beveragepreparation machine are suitable, in particular, for the domestic marketin terms of cost, performance and reliability.

[0005] In the cartridge of WO01/58786 a jet of the beverage is formed bypassing the beverage through an aperture. It has proven difficult toaccurately size and position apertures of this type. The accurate sizingand positioning of the aperture is very important as it is critical tothe correct entrainment of air bubbles in the final beverage. Formingsmall apertures is especially difficult in injection moulded componentswhere the aperture location is internal and surrounded by other portionsof the component. The traditional method of forming an aperture is touse a mould pin sized to the required diameter of the aperture. Howeverapertures formed by mould pins can normally only be directed towards anopening of the component (which opening allows the mould pin access tothe component during moulding). In a beverage cartridge this results inthe beverage being dispensed very quickly out of the opening at speedsup to 12-16 m/s since it is directed directly towards the outlet.

SUMMARY

[0006] Accordingly, the present invention provides a cartridgecontaining one or more beverage ingredients and being formed fromsubstantially air- and water-impermeable materials, said cartridgecomprising an inlet for the introduction of an aqueous medium into thecartridge, and an outlet for a beverage produced from said one or morebeverage ingredients, wherein said cartridge comprises an outer member,an inner member inserted in the outer member and means for producing ajet of the beverage, wherein said means for producing the jet of thebeverage comprises an aperture in a beverage flow path linking the inletto the outlet, characterised in that the aperture is delimited by aninterface between the inner member and the outer member.

[0007] It will be understood that by the term “cartridge” as used hereinis meant any package, container, sachet or receptacle which contains oneor more beverage ingredients in the manner described. The cartridge maybe rigid, semi-rigid or flexible.

[0008] The cartridge of the present invention contains one or morebeverage ingredients suitable for the formation of a beverage product.The beverage product may be, for example, one of coffee, tea, chocolateor a dairy-based beverage including milk. The beverage ingredients maybe powdered, ground, leaf-based or liquid. The beverage ingredients maybe insoluble or soluble. Examples include roast and ground coffee, leaftea, powdered chocolate and soup, liquid milk-based beverages,carbonated drinks and concentrated fruit juices.

[0009] The cartridge of the present invention produces a jet of thebeverage which can be used to alter the appearance and characteristicsof the dispensed beverage, by for example entraining air into the jet ofbeverage to produce a multitude of small air bubbles in the dispensedbeverage. The cartridge of the present invention is easily assembledwith the main components being the inner member and the outer member. Byusing separate components for the inner and outer members which are thenpreferably conjoined on assembly the manufacture of each component andthe assembly of the cartridge can be optimised. This is particularlyadvantageous in the cartridge of the present invention where very smalltolerances are required for the size and location of the aperture thatproduces the jet of beverage and also for the remainder of the beverageflow path through the cartridge. In addition, the aperture can bedirected perpendicular to the overall flow path direction such that thebeverage impacts on a wall or surface of the cartridge and thereby slowsdown before being dispensed. As described above such precision andorientation of the aperture is difficult in injection mouldedcomponents. According to the present invention, this difficulty isovercome by delimiting the aperture by using the interface between theinner member and the outer member rather than by forming the entireaperture in a single component by, for example, a mould pin.

[0010] Preferably, one of the inner member or outer member comprises anopening and the other of the inner member or outer member comprises anobstruction, wherein on insertion of the inner member in the outermember, the obstruction partially obstructs the opening to so delimitthe aperture.

[0011] Advantageously, it is easier to produce a separate opening andobstruction which can be brought together to delimit the aperture.Preferably, the opening comprises an elongated slot, which may beprovided in the inner member. In this case, the outer member comprisesthe obstruction. Preferably, the obstruction comprises an extension ofthe outer member at least a part of which projects into the innermember. The elongated slot may be formed in a cylindrical wall of theinner member. Preferably, the elongated slot extends to the upper edgeof the cylindrical wall. In one embodiment, the extension of the outermember is a cylindrical extension which is received as a sliding fitwithin the cylindrical wall of the inner member. Typically, the aperturehas a cross-sectional area of 0.4 to 0.7 mm².

[0012] Preferably, the cartridge further comprises at least one inletfor air and means for generating a pressure reduction of the jet ofbeverage, whereby, in use, air from the at least one air inlet isincorporated into the beverage as a plurality of small bubbles.Preferably, the at least one air inlet is provided in the inner memberdownstream of the aperture. The inner member may comprise a dischargespout defining the outlet. Preferably, the jet of beverage issuing fromthe aperture is directed into the discharge spout where it may impinge asurface of the discharge spout between issuing from the aperture andexiting the outlet. Preferably, the surface is a concave wall of thedischarge spout. The concave wall is preferably positioned on anopposite side of the discharge spout from the aperture. Preferably, theaperture directs the beverage to flow at an angle substantiallyperpendicular to a flow of beverage out of the outlet. The beverage thushas be to deflected before it can exit the cartridge which results in aslowing of the beverage, which is desired to prevent splashing in thereceptacle.

[0013] The components of the inner member and the outer member may moreeasily be sterilised prior to assembly when they are separated. Once thecomponents are conjoined a number of small-apertured, tortuous pathwaysare created which cannot effectively be sterilised using known methods.The ability to sterilise the components is a particularly advantageousfeature where the cartridges are used for dispensing dairy-basedbeverages.

[0014] Advantageously, the discharge spout is integral with the innermember. The discharge spout serves to direct the discharged beverageinto a receptacle such as a cup. The discharge spout avoids excessivesplashing or spraying of the beverage and is also useful in adjustingthe flow characteristics of the beverage as it is transferred from thecartridge into the receptacle. For example, the discharge spout can beshaped to reduce the degree of turbulence imparted to the beverage toavoid unnecessary reduction in the quantity of bubbles contained in thebeverage. Also advantageously, the cartridge itself comprises thedischarge spout rather than providing a separate discharge spout in abeverage preparation machine. Thus, there is no danger ofcross-contamination of beverage types between dispense cycles since eachdischarge spout is used only once and then disposed of with theremainder of the cartridge. Also, preferably, the beverage dischargedthrough the discharge spout will not contact the outlet mechanism of thebeverage preparation machine thus avoiding soiling of the beveragepreparation machine. Advantageously, the discharge spout and innermember are moulded or otherwise formed as an integral, single unit whichreduces the manufacturing cost of the cartridge and reduces the numberof components which require assembly.

[0015] Preferably, the cartridge is disc-shaped. The outer member and/orinner member are formed, for example, from polypropylene. The cartridgemay be made of a biodegradable polymer.

[0016] In the following description the terms “upper” and “lower” andequivalents will be used to describe the relational positioning offeatures of the invention. The terms “upper” and “lower” and equivalentsshould be understood to refer to the cartridge (or other components) inits normal orientation for insertion into a beverage preparation machineand subsequent dispensing as shown, for example, in FIG. 4. Inparticular, “upper” and “lower” refer, respectively, to relativepositions nearer or further from a top surface 11 of the cartridge. Inaddition, the terms “inner” and “outer” and equivalents will be used todescribe the relational positioning of features of the invention. Theterms “inner” and “outer” and equivalents should be understood to referto relative positions in the cartridge (or other components) being,respectively, nearer or further from a centre or major axis X of thecartridge 1 (or other component).

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Embodiments of the present invention will now be described, byway of example only, with reference to the accompanying drawings, inwhich:

[0018]FIG. 1 is cross-sectional drawing of an outer member of first andsecond embodiments of cartridge, the second embodiment being accordingto the present invention;

[0019]FIG. 2 is a cross-sectional drawing of a detail of the outermember of FIG. 1 showing an inwardly directed cylindrical extension;

[0020]FIG. 3 is a cross-sectional drawing of a detail of the outermember of FIG. 1 showing a slot;

[0021]FIG. 4 is a perspective view from above of the outer member ofFIG. 1;

[0022]FIG. 5 is a perspective view from above of the outer member ofFIG. 1 in an inverted orientation;

[0023]FIG. 6 is a plan view from above of the outer member of FIG. 1;

[0024]FIG. 7 is a cross-sectional drawing of an inner member of thefirst embodiment of cartridge;

[0025]FIG. 8 is a perspective view from above of the inner member ofFIG. 7;

[0026]FIG. 9 is a perspective view from above of the inner member ofFIG. 7 in an inverted orientation;

[0027]FIG. 10 is a plan view from above of the inner member of FIG. 7;

[0028]FIG. 11 is a cross-sectional drawing of the first embodiment ofcartridge in an assembled condition;

[0029]FIG. 12 is a cross-sectional drawing of an inner member of thesecond embodiment of cartridge according to the present invention;

[0030]FIG. 13 is a cross-sectional drawing of a detail of the innermember of FIG. 12 showing an aperture;

[0031]FIG. 14 is a perspective view from above of the inner member ofFIG. 12;

[0032]FIG. 15 is a perspective view from above of the inner member ofFIG. 12 in an inverted orientation;

[0033]FIG. 16 is another cross-sectional drawing of the inner member ofFIG. 12;

[0034]FIG. 17 is a cross-sectional drawing of another detail of theinner member of FIG. 12 showing an air inlet;

[0035]FIG. 18 is a cross-sectional drawing of the second embodiment ofcartridge in an assembled condition;

[0036]FIG. 19 is cross-sectional drawing of an outer member of third andfourth embodiments of cartridge, the fourth embodiment being accordingto the present invention;

[0037]FIG. 20 is a cross-sectional drawing of a detail of the outermember of FIG. 19 showing an inwardly directed cylindrical extension;

[0038]FIG. 21 is a plan view from above of the outer member of FIG. 19;

[0039]FIG. 22 is a perspective view from above of the outer member ofFIG. 19;

[0040]FIG. 23 is a perspective view from above of the outer member ofFIG. 19 in an inverted orientation;

[0041]FIG. 24 is a cross-sectional drawing of an inner member of thethird embodiment of cartridge;

[0042]FIG. 25 is a plan view from above of the inner member of FIG. 24;

[0043]FIG. 26 is a cross-sectional drawing of a detail of the innermember of FIG. 24 showing an in-turned upper rim;

[0044]FIG. 27 is a perspective view from above of the inner member ofFIG. 24;

[0045]FIG. 28 is a perspective view from above of the inner member ofFIG. 24 in an inverted orientation;

[0046]FIG. 29 is a cross-sectional drawing of the third embodiment ofcartridge in an assembled condition;

[0047]FIG. 30 is a cross-sectional drawing of an inner member of thefourth embodiment of cartridge;

[0048]FIG. 31 is a plan view from above of the inner member of FIG. 30;

[0049]FIG. 32 is a perspective view from above of the inner member ofFIG. 30;

[0050]FIG. 33 is a perspective view from above of the inner member ofFIG. 30 in an inverted orientation;

[0051]FIG. 34 is a cross-sectional drawing of the fourth embodiment ofcartridge in an assembled condition;

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0052] As shown in FIG. 11, the cartridge 1 generally comprises an outermember 2, an inner member 3 and a laminate 5. The outer member 2, innermember 3 and laminate 5 are assembled to form the cartridge 1 which hasan interior 120 for containing one or more beverage ingredients, aninlet 121, an outlet 122 and a beverage flow path linking the inlet 121to the outlet 122 and which passes through the interior 120. The inlet121 and outlet 122 are initially sealed by the laminate 5 and are openedin use by piercing or cutting of the laminate 5. The beverage flow pathis defined by spatial inter-relationships between the outer member 2,inner member 3 and laminate 5 as discussed below. Other components mayoptionally be included in the cartridge 1, such as a filter 4, as willbe described further below.

[0053] A first version of cartridge 1 which will be described forbackground purposes is shown in FIGS. 1 to 11. The first version of thecartridge 1 is particularly designed for use in dispensing filteredproducts such as roast and ground coffee or leaf tea. However, thisversion of the cartridge 1 and the other versions described below may beused with other products such as chocolate, coffee, tea, sweeteners,cordials, flavourings, alcoholic beverages, flavoured milk, fruitjuices, squashes, sauces and desserts.

[0054] As can be seen from FIG. 5, the overall shape of the cartridge 1is generally circular or disc-shaped with the diameter of the cartridge1 being significantly greater than its height. A major axis X passesthrough the centre of the outer member as shown in FIG. 1. Typically theoverall diameter of the outer member 2 is 74.5 mm±6 mm and the overallheight is 16 mm±3 mm. Typically the volume of the cartridge 1 whenassembled is 30.2 ml±20%.

[0055] The outer member 2 generally comprises a bowl-shaped shell 10having a curved annular wall 13, a closed top 11 and an open bottom 12.The diameter of the outer member 2 is smaller at the top 11 compared tothe diameter at the bottom 12, resulting from a flaring of the annularwall 13 as one traverses from the closed top 11 to the open bottom 12.The annular wall 13 and closed bottom 11 together define a receptaclehaving an interior 34.

[0056] A hollow inwardly directed cylindrical extension 18 is providedin the closed top 11 centred on the major axis X. As more clearly shownin FIG. 2, the cylindrical extension 18 comprises a stepped profilehaving first, second and third portions 19, 20 and 21. The first portion19 is right circular cylindrical. The second portion 20 isfrusto-conical in shape and is inwardly tapered. The third portion 21 isanother right circular cylinder and is closed off by a lower face 31.The diameter of the first, second and third portion 19, 20 and 21incrementally decreases such that the diameter of the cylindricalextension 18 decreases as one traverses from the top 11 to the closedlower face 31 of the cylindrical extension 18. A generally horizontalshoulder 32 is formed on the cylindrical extension 18 at the junctionbetween the second and third portions 20 and 21.

[0057] An outwardly extending shoulder 33 is formed in the outer member2 towards the bottom 12. The outwardly extending shoulder 33 forms asecondary wall 15 co-axial with the annular wall 13 so as to define anannular track forming a manifold 16 between the secondary wall 15 andthe annular wall 13. The manifold 16 passes around the circumference ofthe outer member 2. A series of slots 17 are provided in the annularwall 13 level with the manifold 16 to provide gas and liquidcommunication between the manifold 16 and the interior 34 of the outermember 2. As shown in FIG. 3, the slots 17 comprise vertical slits inthe annular wall 13. Between 20 and 40 slots are provided. In theembodiment shown thirty-seven slots 17 are provided generallyequi-spaced around the circumference of the manifold 16. The slots 17are preferably between 1.4 and 1.8 mm in length. Typically the length ofeach slot is 1.6 mm representing 10% of the overall height of the outermember 2. The width of each slot is between 0.25 and 0.35 mm. Typically,the width of each slot is 0.3 mm. The width of the slots 17 issufficiently narrow to prevent the beverage ingredients passingtherethrough into the manifold 16 either during storage or in use.

[0058] An inlet chamber 26 is formed in the outer member 2 at theperiphery of the outer member 2. A cylindrical wall 27 is provided, asmost clearly shown in FIG. 5, which defines the inlet chamber 26 within,and partitions the inlet chamber 26 from, the interior 34 of the outermember 2. The cylindrical wall 27 has a closed upper face 28 which isformed on a plane perpendicular to the major axis X and an open lowerend 29 co-planar with the bottom 12 of the outer member 2. The inletchamber 26 communicates with the manifold 16 via two slots 30 as shownin FIG. 1. Alternatively, between one and four slots may be used tocommunicate between the manifold 16 and the inlet chamber 26.

[0059] A lower end of the outwardly extending shoulder 33 is providedwith an outwardly extending flange 35 which extends perpendicularly tothe major axis X. Typically the flange 35 has a width of between 2 and 4mm. A portion of the flange 35 is enlarged to form a handle 24 by whichthe outer member 2 may be held. The handle 24 is provided with anupturned rim 25 to improve grip.

[0060] The outer member 2 is formed as a single integral piece from highdensity polyethylene, polypropylene, polystyrene, polyester, or alaminate of two or more of these materials. A suitable polypropylene isthe range of polymers available from DSM UK Limited (Redditch, UnitedKingdom). The outer member may be opaque, transparent or translucent.The manufacturing process may be injection moulding.

[0061] The inner member 3 as shown in FIGS. 7 to 10, comprises anannular frame 41 and a downwardly extending cylindrical funnel 40. Amajor axis X passes through the centre of the inner member 3 as shown inFIG. 7.

[0062] As best shown in FIG. 8, the annular frame 41 comprises an outerrim 51 and an inner hub 52 joined by ten equi-spaced radial spokes 53.The inner hub 52 is integral with and extends from the cylindricalfunnel 40. Filtration apertures 55 are formed in the annular frame 41between the radial spokes 53. A filter 4 is disposed on the annularframe 41 so as to cover the filtration apertures 55. The filter ispreferably made from a material with a high wet strength, for example anon-woven fibre material of polyester. Other materials which may be usedinclude a water-impermeable cellulosic material, such as a cellulosicmaterial comprising woven paper fibres. The woven paper fibres may beadmixed with fibres of polypropylene, polyvinyl chloride and/orpolyethylene. The incorporation of these plastic materials into thecellulosic material renders the cellulosic material heat-sealable. Thefilter 4 may also be treated or coated with a material which isactivated by heat and/or pressure so that it can be sealed to theannular frame 41 in this way.

[0063] As shown in the cross sectional profile of FIG. 7, the inner hub52 is located at a lower position than the outer rim 51, resulting inthe annular frame 41 having a sloping lower profile.

[0064] The upper surface of each spoke 53 is provided with an upstandingweb 54 which divides a void space above the annular frame 41 into aplurality of passages 57. Each passage 57 is bounded on either side by aweb 54 and on a lower face by the filter 4. The passages 57 extend fromthe outer rim 51 downwardly towards, and open into, the cylindricalfunnel 40 at openings 56 defined by the inner extremities of the webs54.

[0065] The cylindrical funnel 40 comprises an outer tube 42 surroundingan inner discharge spout 43. The outer tube 42 forms the exterior of thecylindrical funnel 40. The discharge spout 43 is joined to the outertube 42 at an upper end of the discharge spout 43 by means of an annularflange 47. The discharge spout 43 comprises an inlet 45 at an upper endwhich communicates with the openings 56 of the passages 57 and an outlet44 at a lower end through which the prepared beverage is discharged intoa cup or other receptacle. The discharge spout 43 comprises afrusto-conical portion 48 at an upper end and a cylindrical portion 58at a lower end. The cylindrical portion 58 may have a slight taper suchthat it narrows towards the outlet 44. The frusto-conical portion 48helps to channel beverage from the passages 57 down towards the outlet44 without inducing turbulence to the beverage. An upper surface of thefrusto-conical portion 48 is provided with four support webs 49equi-spaced around the circumference of the cylindrical funnel 40. Thesupport webs 49 define channels 50 therebetween. The upper edges of thesupport webs 49 are level with one another and perpendicular to themajor axis X.

[0066] The inner member 3 may be formed as a single integral piece frompolypropylene or a similar material as described above and by injectionmoulding in the same manner as the outer member 2.

[0067] Alternatively, the inner member 3 and/or the outer member 2 maybe made from a biodegradable polymer. Examples of suitable materialsinclude degradable polyethylene (for example, SPITEK supplied bySymphony Environmental, Borehamwood, United Kingdom), biodegradablepolyester amide (for example, BAK 1095 supplied by SymphonyEnvironmental), poly lactic acids (PLA supplied by Cargil, Minnesota,USA), starch-based polymers, cellulose derivatives and polypeptides.

[0068] The laminate 5 is formed from two layers, a first layer ofaluminium and a second layer of cast polypropylene. The aluminium layeris between 0.02 and 0.07 mm in thickness. The cast polypropylene layeris between 0.025 and 0.065 mm in thickness. In one embodiment thealuminium layer is 0.06 mm and the polypropylene layer is 0.025 mmthick. This laminate is particularly advantageous as it has a highresistance to curling during assembly. As a result the laminate 5 may bepre-cut to the correct size and shape and subsequently transferred tothe assembly station on the production line without undergoingdistortion. Consequently, the laminate 5 is particularly well suited towelding. Other laminate materials may be used includingPET/Aluminium/PP, PE/EVOH/PP, PET/metallised/PP and Aluminium/PPlaminates. Roll laminate stock may be used instead of die cut stock.

[0069] The cartridge 1 may be closed by a rigid or semi-rigid lidinstead of a flexible laminate.

[0070] Assembly of the cartridge 1 involves the following steps:

[0071] a) the inner member 3 is inserted into the outer member 2;

[0072] b) the filter 4 is cut to shape and placed onto the inner member3 so to be received over the cylindrical funnel 40 and come to restagainst the annular frame 41;

[0073] c) the inner member 3, outer member 2 and filter 4 are joined byultrasonic welding;

[0074] d) the cartridge 1 is filled with one or more beverageingredients;

[0075] e) the laminate 5 is affixed to the outer member 2.

[0076] These steps will be discussed in greater detail below.

[0077] The outer member 2 is orientated with the open bottom 12 directedupwards. The inner member 3 is then inserted into the outer member 2with the outer rim 51 being received as a loose fit in an axialextension 14 at top 11 of the cartridge 1. The cylindrical extension 18of the outer member 2 is at the same time received in the upper portionof the cylindrical funnel 40 of the inner member 3. The third portion 21of the cylindrical extension 18 is seated inside the cylindrical funnel40 with the closed lower face 31 of the cylindrical extension 18 bearingagainst the support webs 49 of the inner member 3. The filter 4 is thenplaced over the inner member 3 such that the filter material contactsthe annular rim 51. An ultrasonic welding process is then used to jointhe filter 4 to the inner member 3 and at the same time, and in the sameprocess step, the inner member 3 to the outer member 2. The inner member3 and filter 4 are welded around the outer rim 51. The inner member 3and outer member 2 are joined by means of weld lines around the outerrim 51 and also the upper edges of the webs 54.

[0078] As shown most clearly in FIG. 11, the outer member 2 and innermember 3 when joined together define a void space 130 in the interior120 below the annular flange 41 and exterior the cylindrical funnel 40which forms a filtration chamber. The filtration chamber 130 andpassages 57 above the annular frame 41 are separated by the filter paper4.

[0079] The filtration chamber 130 contains the one or more beverageingredients 200. The one or more beverage ingredients are packed intothe filtration chamber 130. For a filtered style beverage the ingredientis typically roast and ground coffee or leaf tea. The density of packingof the beverage ingredients in the filtration chamber 130 can be variedas desired. Typically, for a filtered coffee product the filtrationchamber contains between 5.0 and 10.2 grams of roast and ground coffeein a filtration bed of thickness of typically 5 to 14 mm. Optionally,the interior 120 may contain one or more bodies, such as spheres, whichare freely movable within the interior 120 to aid mixing by inducingturbulence and breaking down deposits of beverage ingredients duringdischarge of the beverage.

[0080] The laminate 5 is then affixed to the outer member 2 by forming aweld 126 around the periphery of the laminate 5 to join the laminate 5to the lower surface of the outwardly extending flange 35. The weld 126is extended to seal the laminate 5 against the lower edge of thecylindrical wall 27 of the inlet chamber 26. Further, a weld 125 isformed between the laminate 5 and the lower edge of the outer tube 42 ofthe cylindrical funnel 40. The laminate 5 forms the lower wall of thefiltration chamber 130 and also seals the inlet chamber 26 andcylindrical funnel 40. However, a small gap 123 exists prior todispensation between the laminate 5 and the lower edge of the dischargespout 43. A variety of welding methods may be used, such as heat andultrasonic welding, depending on the material characteristics of thelaminate 5.

[0081] Advantageously, the inner member 3 spans between the outer member2 and the laminate 5. The inner member 3 is formed from a material ofrelative rigidity, such as polypropylene. As such, the inner member 3forms a load-bearing member that acts to keep the laminate 5 and outermember 2 spaced apart when the cartridge 1 is compressed. It ispreferred that the cartridge 1 is subjected to a compressive load ofbetween 130 and 280N in use. The compressive force acts to prevent thecartridge failing under internal pressurisation and also serves tosqueeze the inner member 3 and outer member 2 together. This ensuresthat the internal dimensions of passageways and apertures in thecartridge 1 are fixed and unable to change during pressurisation of thecartridge 1.

[0082] To use the cartridge 1 it is first inserted into a beveragepreparation machine and the inlet 121 and outlet 122 are opened bypiercing members of the beverage preparation machine which perforate andfold back the laminate 5. An aqueous medium, typically water, underpressure enters the cartridge 1 through the inlet 121 into the inletchamber 26 at a pressure of between 0.1-2.0 bar (10-200 KPa). From therethe water is directed to flow through the slots 30 and round themanifold 16 and into the filtration chamber 130 of the cartridge 1through the plurality of slots 17. The water is forced radially inwardlythrough the filtration chamber 130 and mixes with the beverageingredients 200 contained therein. The water is at the same time forcedupwardly through the beverage ingredients. The beverage formed bypassage of the water through the beverage ingredients passes through thefilter 4 and filtration apertures 55 into the passages 57 lying abovethe annular frame 41. The sealing of the filter 4 onto the spokes 53 andthe welding of the rim 51 with the outer member 2 ensures that there areno short-circuits and all the beverage has to pass through the filter 4.

[0083] The beverage then flows downwardly along the radial passages 57formed between the webs 54 and through the openings 56 and into thecylindrical funnel 40. The beverage passes along the channels 50 betweenthe support webs 47 and down the discharge spout 43 to the outlet 44where the beverage is discharged into a receptacle such as a cup.

[0084] Preferably, the beverage preparation machine comprises an airpurge facility, wherein compressed air is forced through the cartridge 1at the end of the dispense cycle to flush out the remaining beverageinto the receptacle.

[0085] A second version of cartridge 1 embodying the present inventionwill now be described with reference to FIGS. 12 to 18. The secondversion of the cartridge 1 is particularly designed for use indispensing espresso-style products such as roast and ground coffee whereit is desirable to produce a beverage having a froth of tiny bubblesknown as a crema. Many of the features of the second version of thecartridge 1 are the same as in the first version and like numerals havebeen used to reference like features. In the following description thedifferences between the first and second versions will be discussed.Common features which function in the same manner will not be discussedin detail.

[0086] The outer member 2 is of the same construction as in the firstversion of cartridge 1 and as shown in FIGS. 1 to 6.

[0087] The annular frame 41 of the inner member 3 is the same as in thefirst version. Also, a filter 4 is disposed on the annular frame 41 soas to cover the filtration apertures 55. The outer tube 42 of thecylindrical funnel 40 is also as before. However, there are a number ofdifferences in the construction of the inner member 2 of the secondversion compared to the first version. As shown in FIG. 16, thedischarge spout 43 is provided with a partition 65 which extends partway up the discharge spout 43 from the outlet 44. The partition 65 helpsto prevent the beverage spraying and/or splashing as it exits thedischarge spout 43. The profile of the discharge spout 43 is alsodifferent and comprises a stepped profile with a distinct dog-leg 66near an upper end of the tube 43.

[0088] A rim 67 is provided upstanding from the annular flange 47joining the outer tube 42 to the discharge spout 43. The rim 67surrounds the inlet 45 to the discharge spout 43 and defines an annularchannel 69 between the rim 67 and the upper portion of the outer tube42. The rim 67 is provided with an inwardly directed shoulder 68. At onepoint around the circumference of the rim 67 an aperture 70 is providedin the form of a slot which extends from an upper edge of rim 67 to apoint marginally below the level of the shoulder 68 as most clearlyshown in FIGS. 12 and 13. The slot has a width of 0.64 mm.

[0089] An air inlet 71 is provided in annular flange 47circumferentially aligned with the aperture 70 as shown in FIGS. 16 and17. The air inlet 71 comprises an aperture passing through the flange 47so as to provide communication between a point above the flange 47 andthe void space below the flange 47 between the outer tube 42 anddischarge spout 43. Preferably, and as shown, the air inlet 71 comprisesan upper frusto-conical portion 73 and a lower cylindrical portion 72.The air inlet 71 is typically formed by a mould tool such as a pin. Thetapered profile of the air inlet 71 allows the mould tool to be moreeasily removed from the moulded component. The wall of the outer tube 42in the vicinity of the air inlet 71 is shaped to form a chute 75 leadingfrom the air inlet 71 to the inlet 45 of the discharge spout 43. Asshown in FIG. 17, a canted shoulder 74 is formed between the air inlet71 and the chute 75 to ensure that the jet of beverage issuing from theslot 70 does not immediately foul on the upper surface of the flange 47in the immediate vicinity of the air inlet 71.

[0090] The assembly procedure for the second version of cartridge 1 issimilar to the assembly of the first version. However, there are certaindifferences. As shown in FIG. 18, the third portion 21 of thecylindrical extension 18 is seated inside the support rim 67 rather thanagainst support webs. The shoulder 32 of the cylindrical extension 18between the second portion 20 and third portion 21 bears against theupper edge of the support rim 67 of the inner member 3. An interfacezone 124 is thus formed between the inner member 3 and the outer member2 comprising a face seal between the cylindrical extension 18 and thesupport rim 67 which extends around nearly the whole circumference ofthe cartridge 1. The seal between the cylindrical extension 18 and thesupport rim 67 is not fluid-tight though since the slot 70 in thesupport rim 67 extends through the support rim 67 and downwardly to apoint marginally below the shoulder 68. Consequently the interface fitbetween the cylindrical extension 18 and the support rim 67 transformsthe slot 70 into an aperture 128, as most clearly shown in FIG. 18,providing gas and liquid communication between the annular channel 69and the discharge spout 43. The aperture is typically 0.64 mm wide by0.69 mm long.

[0091] Operation of the second version of cartridge 1 to dispense abeverage is similar to the operation of the first version but withcertain differences. Beverage in the radial passages 57 flows downwardlyalong the passages 57 formed between the webs 54 and through theopenings 56 and into the annular channel 69 of the cylindrical funnel40. From the annular channel 69 the beverage is forced under pressurethrough the aperture 128 by the back pressure of beverage collecting inthe filtration chamber 130 and passages 57. The beverage is thus forcedthrough aperture 128 as a jet and into an expansion chamber formed bythe upper end of the discharge spout 43. As shown in FIG. 18, the jet ofbeverage passes directly over the air inlet 71. As the beverage entersthe discharge spout 43 the pressure of the beverage jet drops. As aresult air is entrained into the beverage stream in the form of amultitude of small air bubbles as the air is drawn up through the airinlet 71. The jet of beverage issuing from the aperture 128 is funnelleddownwards to the outlet 44 where the beverage is discharged into areceptacle such as a cup where the air bubbles form the desired crema.Thus, the aperture 128 and the air inlet 71 together form an eductorwhich acts to entrain air into the beverage. Flow of beverage into theeductor should be kept as smooth as possible to reduce pressure losses.Advantageously, the walls of the eductor should be made concave toreduce losses due to ‘wall effect’ friction. The dimensional toleranceof the aperture 128 is small. Preferably the aperture size is fixed plusor minus 0.02 mm². Hairs, fibrils or other surface irregularities can beprovided within or at the exit of the eductor to increase the effectivecross-sectional area which has been found to increase the degree of airentrainment.

[0092] A third version of cartridge 1 will now be described forbackground purposes and is shown in FIGS. 19 to 29. The third version ofthe cartridge 1 is particularly designed for use in dispensing solubleproducts which may be in powdered, liquid, syrup, gel or similar form.The soluble product is dissolved by or forms a suspension in, an aqueousmedium such as water when the aqueous medium is passed, in use, throughthe cartridge 1. Examples of beverages include chocolate, coffee, milk,tea, soup or other rehydratable or aqueous-soluble products. Many of thefeatures of the third version of the cartridge 1 are the same as in theprevious versions and like numerals have been used to reference likefeatures. In the following description the differences between the thirdand previous versions will be discussed. Common features which functionin the same manner will not be discussed in detail.

[0093] Compared to the outer member 2 of the previous versions, thehollow inwardly directed cylindrical extension 18 of the outer member 2of the third version has a larger overall diameter as shown in FIG. 20.In particular the diameter of the first portion 19 is typically between16 and 18 mm compared to 13.2 mm for the outer member 2 of the previousversions. In addition, the first portion 19 is provided with a convexouter surface 19 a, or bulge, as most clearly shown in FIG. 20, thefunction of which will be described below. The diameter of the thirdportions 21 of the cartridges 1 are however the same resulting in thearea of the shoulder 32 being greater in this, the third version of thecartridge 1. Typically the volume of the cartridge 1 when assembled is32.5 ml±20%.

[0094] The number and positioning of the slots in the lower end of theannular wall 13 is also different. Between 3 and 5 slots are provided.In the embodiment as shown in FIG. 23, four slots 36 are providedequi-spaced around the circumference of the manifold 16. The slots 36are slightly wider than in the previous versions of the cartridge 1being between 0.35 and 0.45 mm, preferably 0.4 mm wide.

[0095] In other respects the outer members 2 of the cartridges 1 are thesame.

[0096] The construction of the cylindrical funnel 40 of the inner member3 is the same as in the first version of cartridge 1 with an outer tube42, discharge spout 45, annular flange 47 and support webs 49 beingprovided. The only difference is that the discharge spout 45 is shapedwith an upper frusto-conical section 92 and a lower cylindrical section93.

[0097] In contrast to the previous versions and as shown in FIGS. 24 to28, the annular frame 41 is replaced by a skirt portion 80 whichsurrounds the cylindrical funnel 40 and is joined thereto by means ofeight radial struts 87 which adjoin the cylindrical funnel 40 at or nearthe annular flange 47. A cylindrical extension 81 of the skirt portion80 extends upwardly from the struts 87 to define a chamber 90 with anopen upper face. An upper rim 91 of the cylindrical extension 81 has anin-turned profile as shown in FIG. 26. An annular wall 82 of the skirtportion 80 extends downwardly from the struts 87 to define an annularchannel 86 between the skirt portion 80 and the outer tube 42.

[0098] The annular wall 82 comprises at a lower end an exterior flange83 which lies perpendicular to the major axis X. A rim 84 dependsdownwardly from a lower surface of the flange 83 and contains fiveapertures 85 which are circumferentially equi-spaced around the rim 84.Thus, the rim 84 is provided with a castellated lower profile.

[0099] Apertures 89 are provided between the struts 87 allowingcommunication between the chamber 90 and the annular channel 86.

[0100] The assembly procedure for the third version of cartridge 1 issimilar to the assembly of the first version but with certaindifferences. The outer member 2 and inner member 3 are push-fittedtogether as shown in FIG. 29 and retained by means of a snap-fitarrangement rather than welded together. On joining the two members theinwardly directed cylindrical extension 18 is received inside the uppercylindrical extension 81 of the skirt portion 80. The inner member 3 isretained in the outer member 2 by frictional interengagement of theconvex outer surface 19 a of the first portion 19 of the cylindricalextension 18 with the in-turned rim 91 of the upper cylindricalextension 81. With the inner member 3 located in the outer member 2 amixing chamber 134 is defined located exterior to the skirt portion 80.The mixing chamber 134 contains the beverage ingredients 200 prior todispensation. It should be noted that the four inlets 36 and the fiveapertures 85 are staggered circumferentially with respect to oneanother. The radial location of the two parts relative to each otherneed not be determined or fixed during assembly since the use of fourinlets 36 and five apertures 85 ensures that misalignment occurs betweenthe inlets and apertures whatever the relative rotational positioning ofthe components.

[0101] The one or more beverage ingredients are packed into the mixingchamber 134 of the cartridge. The density of packing of the beverageingredients in the mixing chamber 134 can be varied as desired.

[0102] The laminate 5 is then affixed to the outer member 2 and innermember 3 in the same manner as described above in the previous versions.

[0103] In use, water enters the mixing chamber 134 through the fourslots 36 in the same manner as previous versions of the cartridge. Thewater is forced radially inwardly through the mixing chamber and mixeswith the beverage ingredients contained therein. The product isdissolved or mixed in the water and forms the beverage in the mixingchamber 134 and is then driven though the apertures 85 into the annularchannel 86 by back pressure of beverage and water in the mixing chamber134. The circumferential staggering of the four inlet slots 36 and thefive apertures 85 ensures that jets of water are not able to passradially directly from the inlet slots 36 to the apertures 85 withoutfirst circulating within the mixing chamber 134. In this way the degreeand consistency of dissolution or mixing of the product is significantlyincreased. The beverage is forced upwardly in the annular channel 86,through the apertures 89 between the struts 87 and into the chamber 90.The beverage passes from chamber 90 through the inlets 45 between thesupport webs 49 into the discharge spout 43 and towards the outlet 44where the beverage is discharged into a receptacle such as a cup. Thecartridge finds particular application with beverage ingredients in theform of viscous liquids or gels. In one application a liquid chocolateingredient is contained in the cartridge 1 with a viscosity of between1700 and 3900 mPa at ambient temperature and between 5000 and 10000 mPaat 0° C. and a refractive solids of 67 Brix±3. In another applicationliquid coffee is contained in the cartridge 1 with a viscosity ofbetween 70 and 20 mPa at ambient and between 80 and 50000 mPa at 0° C.where the coffee has a total solids level of between 40 and 70%.

[0104] A fourth version of cartridge 1 embodying the present inventionis shown in FIGS. 30 to 34. The fourth version of the cartridge 1 isparticularly designed for use in dispensing liquid products such asconcentrated liquid milk. Many of the features of the fourth version ofthe cartridge 1 are the same as in the previous versions and likenumerals have been used to reference like features. In the followingdescription the differences between the fourth and previous versionswill be discussed. Common features which function in the same mannerwill not be discussed in detail.

[0105] The outer member 2 is the same as in the third version ofcartridge 1 and as shown in FIGS. 19 to 23.

[0106] The cylindrical funnel 40 of the inner member 3 is similar tothat shown in the second version of cartridge 1 but with certaindifferences. As shown in FIG. 30 the discharge spout 43 is shaped withan upper frusto-conical section 106 and a lower cylindrical section 107.Three axial ribs 105 are provided on the inner surface of the dischargespout 43 to direct the dispensed beverage downwards towards the outlet44 and prevent the discharged beverage from spinning within the spout.Consequently, the ribs 105 act as baffles. As in the second version ofcartridge 1, an air inlet 71 is provided through the annular flange 47.However, the chute 75 beneath the air inlet 71 is more elongated than inthe second version.

[0107] A skirt portion 80 is provided similar to that shown in the thirdversion of the cartridge 1 described above. Between 5 and 12 apertures85 are provided in the rim 84. Typically ten apertures are providedrather than the five provided in the third version of cartridge 1.

[0108] An annular bowl 100 is provided extending from and integral withthe flange 83 of the skirt portion 80. The annular bowl 100 comprises aflared body 101 with an open upper mouth 104 which is directed upwards.Four feed apertures 103 shown in FIGS. 30 and 31 are located in the body101 at or near the lower end of the bowl 100 where it joins the skirtportion 80. Preferably, the feed apertures are equi-spaced around thecircumference of the bowl 100.

[0109] The laminate 5 is of the type described above in the previousembodiments.

[0110] The assembly procedure for the fourth version of cartridge 1 isthe same as that for the third version.

[0111] Operation of the fourth version of cartridge is similar to thatof the third version. The water enters the cartridge 1 and the mixingchamber 134 in the same manner as before. There the water mixes with anddilutes the liquid product which is then forced out through theapertures 85 towards the outlet 44 as described above. A proportion ofthe liquid product is initially contained within the annular bowl 100 asshown in FIG. 34 and is not subject to immediate dilution by the waterentering the mixing chamber 134. The diluted liquid product in the lowerpart of the mixing chamber 134 will tend to exit through apertures 85rather than be forced up and into the annular bowl 100 through uppermouth 104. Consequently, the liquid product in the annular bowl 100 willremain relatively concentrated compared to the product in the lower partof the mixing chamber 134. The liquid product in the annular bowl 100drips through the feed apertures 103 into the stream of product exitingthe mixing chamber 134 through the apertures 85. The annular bowl 100acts to even out the concentration of the diluted liquid productentering the cylindrical funnel 40 by holding back a proportion of theconcentrated liquid product and releasing it into the exiting liquidstream more steadily throughout the dispensation cycle.

[0112] From the annular channel 86 the beverage is forced under pressurethrough the aperture 128 by the back pressure of beverage collecting inthe filtration chamber 134 and chamber 90. The beverage is thus forcedthrough aperture 128 as a jet and into an expansion chamber formed bythe upper end of the discharge spout 43. As shown in FIG. 34, the jet ofbeverage passes directly over the air inlet 71. As the beverage entersthe discharge spout 43 the pressure of the beverage jet drops. As aresult air is entrained into the beverage stream in the form of amultitude of small air bubbles as the air is drawn up through the airinlet 71. The jet of beverage issuing from the aperture 128 is funnelleddownwards to the outlet 44 where the beverage is discharged into areceptacle such as a cup where the air bubbles form the desired frothyappearance.

[0113] Advantageously, the inner member 3, outer member 2, laminate 5and filter 4 can all be readily sterilised due to the components beingseparable and not individually comprising tortuous passageways or narrowcrevices. Rather, it is only after conjoining the components, aftersterilisation, that the necessary passageways are formed. This isparticularly important where the beverage ingredient is a dairy-basedproduct such as liquid milk concentrate.

[0114] The fourth embodiment of beverage cartridge is particularlyadvantageous for dispensing a concentrated dairy-based liquid productsuch as liquid milk. Previously, powdered milk products have beenprovided in the form of sachets for adding to a pre-prepared beverage.However, for a cappuccino-style beverage it is necessary to foam themilk. This has been achieved previously by passing steam through aliquid milk product. However this necessitates the provision of a steamsupply which increases the cost and complexity of the machine used todispense the beverage. The use of steam also increases the risk ofinjury during operation of the cartridge. Accordingly the presentinvention provides for a beverage cartridge having a concentrateddairy-based liquid product therein. It has been found that byconcentrating the milk product a greater amount of foam can be producedfor a particular volume of milk when compared to fresh or UHT milk. Thisreduces the size required for the milk cartridge. Fresh semi-skimmedmilk contains approximately 1.6% fat and 10% total solids. Theconcentrated liquid milk preparations of the present invention containbetween 3 and 10% fat and 25 to 40% total solids. In a typical example,the preparation contains 4% fat and 30% total solids. The concentratedmilk preparations are suitable for foaming using a low pressurepreparation machine as will be described below. In particular, foamingof the milk is achieved at pressures below 2 bar, preferablyapproximately 1.5 bar (150 KPa) using the cartridge of the fourthembodiment described above.

[0115] The cartridge of the fourth embodiment is also advantageous indispensing liquid coffee products.

[0116] It has been found that the embodiments of beverage cartridge ofthe present invention advantageously provide an improved consistency ofthe dispensed beverage when compared to prior art cartridges. Referenceis made to Table 1 below which shows the results of brew yields fortwenty samples each of cartridges A and B containing roast and groundcoffee. Cartridge A is a beverage cartridge according to the firstembodiment of the present invention. Cartridge B is a prior art beveragecartridge as described in the applicant's document WO01/58786. Therefractive index of the brewed beverage is measured in Brix units andconverted to a percentages of soluble solids (% SS) using standardtables and formulae. In the examples below:

% SS=0.7774*(Brix value)+0.0569.

& Yield=(% SS*Brew Volume (g))/(100*Coffee Weight (g)) TABLE 1 CARTRIDGEA Brew Sample Volume (g) Coffee Weight (g) Brix % SS (*) % Yield 1 105.66.5 1.58 1.29 20.88 2 104.24 6.5 1.64 1.33 21.36 3 100.95 6.5 1.67 1.3621.05 4 102.23 6.5 1.71 1.39 21.80 5 100.49 6.5 1.73 1.40 21.67 6 107.546.5 1.59 1.29 21.39 7 102.70 6.5 1.67 1.36 21.41 8 97.77 6.5 1.86 1.5022.61 9 97.82 6.5 1.7  1.38 20.75 10 97.83 6.5 1.67 1.36 20.40 11 97.66.5 1.78 1.44 21.63 12 106.64 6.5 1.61 1.31 21.47 13 99.26 6.5 1.54 1.2519.15 14 97.29 6.5 1.59 1.29 19.35 15 101.54 6.5 1.51 1.23 19.23 16104.23 6.5 1.61 1.31 20.98 17 97.5 6.5 1.73 1.40 21.03 18 100.83 6.51.68 1.36 21.14 19 101.67 6.5 1.67 1.36 21.20 20 101.32 6.5 1.68 1.3621.24 AVERAGE 20.99

[0117] CARTRIDGE B Brew Sample Volume (g) Coffee Weight (g) Brix % SS(*) % Yield 1 100.65 6.5 1.87 1.511 23.39 2 95.85 6.5 1.86 1.503 22.16 398.4 6.5 1.8 1.456 22.04 4 92.43 6.5 2.3 1.845 26.23 5 100.26 6.5 1.721.394 21.50 6 98.05 6.5 2.05 1.651 24.90 7 99.49 6.5 1.96 1.581 24.19 895.62 6.5 2.3 1.845 27.14 9 94.28 6.5 2.17 1.744 25.29 10 96.13 6.5 1.721.394 20.62 11 96.86 6.5 1.81 1.464 21.82 12 94.03 6.5 2.2 1.767 25.5613 96.28 6.5 1.78 1.441 21.34 14 95.85 6.5 1.95 1.573 23.19 15 95.36 6.51.88 1.518 22.28 16 92.73 6.5 1.89 1.526 21.77 17 88 6.5 1.59 1.29317.50 18 93.5 6.5 2.08 1.674 24.08 19 100.88 6.5 1.75 1.417 22.00 2084.77 6.5 2.37 1.899 24.77 AVERAGE 23.09

[0118] Performing a t-test statistical analysis on the above data givesthe following results: TABLE 2 t-Test: Two-Sample Assuming EqualVariances % Yield % Yield (Cartridge A) (Cartridge B) Mean 20.99 23.09Variance 0.77 5.04 Observations 20 20 Pooled Variance 2.90 HypothesizedMean Difference 0 df 38 t Stat −3.90 P(T <= t) one-tail 0.000188 tCritical one-tail 1.686 P(T <= t) two-tail 0.000376 t Critical two-tail2.0244 Standard Deviation 0.876 2.245

[0119] The analysis shows that the consistency of % yield, which equatesto brew strength, for the cartridges of the present invention issignificantly better (at a 95% confidence level) than the prior artcartridges, with a standard deviation of 0.88% compared to 2.24%. Thismeans that beverages dispensed with the cartridges of the presentinvention have a more repeatable and uniform strength. This is preferredby consumers who like their drinks to taste the same time after time anddo not want arbitrary changes in drink strength.

[0120] The materials of the cartridges described above may be providedwith a barrier coating to improve their resistance to oxygen and/ormoisture and/or other contaminant ingress. The barrier coating may alsoimprove the resistance to leakage of the beverage ingredients fromwithin the cartridges and/or reduce the degree of leaching ofextractibles from the cartridge materials which might adversely affectthe beverage ingredients. The barrier coating may be of a materialselected from the group of PET, Polyamide, EVOH, PVDC or a metallisedmaterial. The barrier coating may be applied by a number of mechanismsincluding but not limited to vapour deposition, vacuum deposition,plasma coating, co-extrusion, in-mould labelling and two/multi-stagemoulding.

1. A cartridge containing one or more beverage ingredients and beingformed from substantially air- and water-impermeable materials, saidcartridge comprising an inlet for the introduction of an aqueous mediuminto the cartridge, and an outlet for a beverage produced from said oneor more beverage ingredients, wherein said cartridge comprises an outermember, an inner member inserted in the outer member and means forproducing a jet of the beverage, wherein said means for producing thejet of the beverage comprises an aperture in a beverage flow pathlinking the inlet to the outlet, characterised in that the aperture isdelimited by an interface between the inner member and the outer member.2. A cartridge as claimed in claim 1 wherein one of the inner member orouter member comprises an opening and the other of the inner member orouter member comprises an obstruction, wherein on insertion of the innermember in the outer member, the obstruction partially obstructs theopening to so delimit the aperture
 3. A cartridge as claimed in claim 2wherein the opening comprises an elongated slot.
 4. A cartridge asclaimed in claim 3 wherein the inner member comprises said elongatedslot.
 5. A cartridge as claimed in claim 4 wherein the outer membercomprises the obstruction.
 6. A cartridge as claimed in claim 5 whereinthe obstruction comprises an extension of the outer member at least apart of which projects into the inner member.
 7. A cartridge as claimedin claim 6 wherein the elongated slot is formed in a cylindrical wall ofthe inner member.
 8. A cartridge as claimed in claim 7 wherein theelongated slot extends to the upper edge of the cylindrical wall.
 9. Acartridge as claimed in claim 7 wherein the extension of the outermember is a cylindrical extension which is received as a sliding fitwithin the cylindrical wall of the inner member.
 10. A cartridge asclaimed in claim 9 wherein the aperture has a cross-sectional area of0.4 to 0.7 mm².
 11. A cartridge as claimed in claim 10 furthercomprising at least one inlet for air and means for generating apressure reduction of the jet of beverage, whereby, in use, air from theat least one air inlet is incorporated into the beverage as a pluralityof small bubbles.
 12. A cartridge as claimed in claim 11 wherein the atleast one air inlet is provided in the inner member downstream of theaperture.
 13. A cartridge as claimed in claim 12 wherein the innermember comprises a discharge spout defining the outlet.
 14. A cartridgeas claimed in claim 13 wherein the jet of beverage issuing from theaperture is directed into the discharge spout.
 15. A cartridge asclaimed in claim 14 wherein the jet of beverage impinges a surface ofthe discharge spout between issuing from the aperture and exiting theoutlet.
 16. A cartridge as claimed in claim 15 wherein the surface is aconcave wall of the discharge spout.
 17. A cartridge as claimed in claim16 wherein the concave wall is positioned on an opposite side of thedischarge spout from the aperture.
 18. A cartridge as claimed in claim17 wherein the aperture directs the beverage to flow at an anglesubstantially perpendicular to a flow of beverage out of the outlet. 19.A cartridge as claimed in claim 18 wherein the discharge spout isintegral with the inner member.
 20. A cartridge as claimed in claim 19wherein the cartridge is disc-shaped.
 21. A cartridge as claimed inclaim 20 wherein the outer member and/or inner member are formed frompolypropylene.
 22. A cartridge as claimed in claim 21 wherein the outermember and/or inner member are formed from a biodegradable polymer. 23.A cartridge as claimed in claim 22 wherein the outer member and/or innermember is formed by injection moulding.